PolyBase - Added support for reading, writing, and querying Parquet files, improved error messages for rejected rows via PolyBase imports, and fixed an issue where credentials would not be refreshed when dropping or re-creating an external table.

SQL features - Changed default table indexes to Clustered ColumnStore indexes, added support for RENAME OBJECT, and added more DMVs for performance troubleshooting.

Performance and stability - Fixed a defect that could cause uneven data loading in round robin tables, fixed a connection issue for long running queries, and made pause, resume, and scaling operation stability improvements.